Removing Fuel Tank
Removing Fuel Tank
Required tools
Item 1 - 3:
Removing fuel tank
NOTE:
- The repair procedure may vary depending on engine type and country equipment. This relates in particular to components in the right wheel housing.
- The description relates to ORVR vehicles.
- Sealing rings must generally be replaced.
The following exploded drawing shows the attachment of the fuel filler neck and carbon canister in the right wheel housing.
No. 1 - 7:
The following exploded drawing shows how the fuel tank is attached to the vehicle floor.
No. 1 - 9:
WARNING:
Danger of fire.
- Keep clear of ignition sources.
- Do not smoke.
- Danger of fire due to naked flames and sparks, e.g. during welding or grinding work.
- Danger of fire due to escaping fuel, e.g. on hot engine components or due to electrostatic charge.
- Danger of fire due to hot exhaust system. Always allow the exhaust system to cool down.
- Secure the vehicle, e.g. with a warning sign.
- Change any clothing soaked with fuel immediately.
- In case of fire, use CO(2) or dry powder fire extinguishers.
CAUTION:
- Observe general warning notes and working regulations.
- For safety reasons, the tank should only be removed and installed when empty
1. Position the vehicle at the take-up points provided using a lifting platform so that trim panels and the suspension subframe can be removed.
2. Deactivate air suspension. Bleed rear axle of air suspension using PST.
3. For Tiptronic vehicles, shift transmission to N.
NOTE: All windows should be opened for better ventilation in the passenger compartment.
4. Open filler flap.
5. Fold rear seat forwards.
6. Fold up the retaining brackets of the right-hand belt anchor. To do so, undo the three fastening screws and fold up the bracket with the belt anchor. Do not use the fastening screws again.
7. Undo the right cap (figure shows both). To do so, cut out the carpeted floor along the perforated lines using a carpet knife and fold it over. Then unscrew the four fastening nuts and remove the lid.
8. Carefully remove the fuel supply -1- at the right connection unit and loosen the two disconnection points -2 and 3-. Also remove line (not shown here) in vehicles with auxiliary heating (auxiliary heater).
CAUTION:
- Fuel vapours will penetrate the passenger compartment when you open the locking unit. Ventilate the vehicle well
- Do not spill fuel into the passenger compartment
9. Drain the tank.
10. Screw the tank cap down. Then remove the rubber sleeve around the fuel filler neck, loosen the two fastening screws (M6 x 20) and remove the ground cable.
11. Remove rear wheels.
12. Remove rear right wheel housing liner.
CAUTION:
Risk of damage
- Lines can become kinked or can crack.
- Never leave carbon canister hanging freely on the lines.
- A second person should hold the carbon canister during removal.
13. Loosen the five fastening screws on the carbon canister and the two on the degassing tank in the right wheel housing -arrows-.
NOTE: In USA vehicles, the rubber hose -2- of the leak diagnosis pump is extremely tight. If the hose is pulled, the filler neck can break off at the leak diagnosis pump.
14. Carefully remove the two electric plugs -3- on the carbon canister and on the leak diagnosis pump and the hose on the filler neck -2- of the leak diagnosis pump (USA). There is always a risk of damage. Then, disconnect plastic line -1-.
15. Cut through the tie-wraps of the ground cable on the carbon canister and take the carbon canister out of the wheel well. Replace tie-wraps.
16. Remove hose connection on the degassing tank.
17. Pull filler neck and degassing tank out of the wheel well and secure with a piece of wire -arrow- (figure shows degassing tank with carbon canister).
18. Pull hand brake cable out of the rear brakes and lay it aside.
CAUTION: Remove the sheetmetal clips of the hand brake cable carefully as they bend very easily.
19. Carefully remove the sheetmetal clips of the hand brake cable on the fuel tank.
20. Remove cable plug of the brake pad wear indicator -1-. Unscrew the rear brake calipers on the left and right of the wheel bearing housing -2-. To do this, loosen the two internal serration screws. Secure the brake calipers with a piece of wire to prevent it from falling down. Replace internal serration screws.
21. Then, loosen the stone shield on the right side. Remove screws -2-.
22. Remove line holder under the stone shield by pressing on the centre plug -arrow-. Replace line holder.
CAUTION:
Danger of injury.
- Exhaust system parts are heavy.
- Before releasing the exhaust system make sure that it cannot fall down.
23. Remove exhaust system up to disconnection point for main catalytic converter. To do this, release the connecting straps between the catalytic converters and the exhaust system. Then push the straps backwards onto the exhaust system. The exhaust straps must not be re-used.
24. Release the front and middle retainers. To do this, loosen the 2 fastening screws.
NOTE: Before the rear silencer is released, the exhaust system must be supported with a transmission jack or held by another person.
25. Unscrew the fastening screws on the left and right of the rear silencer.
26. Remove exhaust system.
Figure shows exhaust system on transmission jack
27. Remove rear cardan shaft.
28. Mark position of the cardan shaft-arrow-onthe rear axle transmission flange with a coloured pen.
29. Mark position of the cardan shaft-arrow-onthe transfer box flange with a coloured pen.
NOTE: To release the cardan shaft on the rear axle transmission a second fitter should counter the triangular flange of the transfer box.
30. Unscrew fastening screws on the cardan shaft on the rear axle transmission.
31. Unscrew fastening screws-arrow-onthe cardan shaft on the transfer box. Counter with an open-ended wrench.
NOTE: To prevent the cardan shaft from being damaged, a second mechanic is required to remove the equipment.
32. Release cardan shaft centre bearing holder. To do this, unscrew six fastening screws -arrow-.
33. Carefully separate cardan shaft from transfer box and press backwards.
34. Remove cardan shaft.
35. Disconnect rear axle transmission ventilation tube on the rear axle. To do this, press the plastic connector and pull it off.
36. Disconnect the electric plugs -2- on the rear left side member and then clip on the electric cable from the sheetmetal holder -1-.
37. Disconnect the electric plug -1- on the rear right side member and then clip on the electric cable from the sheetmetal holder -2-.
NOTE:
- In the case of vehicles with air suspension, the compressed air line on the spring strut must also be disconnected. Loosen the line carefully and allow the remaining pressure to escape. Undo the screws completely only when the line is fully depressurised.
- The electrical plug connection of the height sensor must be disconnected in vehicles with air suspension or automatic headlight beam adjustment.
38. Unscrew the four fastening screws (M12 x 80) of the top damper housing-arrows-.Fastening screws must be replaced.
39. Loosen the four suspension subframe screws by approx. one turn.
NOTE: The lifting platform must be set up in order to remove the rear axle. These are the mandrels with double digits (1/11 and 2/22). Set up these mandrels at the corresponding position (11 and 22) on the bar.
40. Place the lifting platform under the rear axle and guide into this using the mounting mandrels.
41. Undo the four fastening screws on the rear axle and lower the lifting platform slowly. The fastening screws must not be re-used.
NOTE: When lowering the rear axle, watch out for the hand brake cable and pull this out of the rear axle.
42. Remove the rear axle and put the lifting platform aside.
43. Remove the centre underbody cover at the left and right of the longitudinal side members.
44. Remove rear heat shield. To do so, undo the three sheetmetal nuts and the two screws
45. Undo the tank attachment band, which runs in the direction of travel -arrows-. Then, position a transmission jack under the tank and secure the tank from falling using a belt. When doing so, make sure that the fuel lines are not damaged.
46. Undo and remove the remaining restraining straps. Slowly lower the tank with the transmission jack. Also guide the degassing tank in the right wheel housing.
